Recent collecting from the Hell's Mouth Grits of St. Tudwal's Peninsula, North Wales, enables an assessment to be made of the taxonomy and stratigraphical position of the Cambrian faunas first reported by D. A. Bassett in 1960 (in Bassett, D. A. & Walton, E. K., Q. Jl Geol. Soc. Lond.116, 103). New species of protolenid and eodiscid trilobites are present, together with a brachiopod, sponge spicules and trace fossils.